Pure Photonics is a manufacturer of low-noise tunable lasers, based on the high-volume Tunable External Cavity Laser (ECL) technology by Lumentu. Pure Photonics is modifying this superior and field-proven tunable laser for the Telecom industry to meet the stringent requirements of Sensing and Scientific applications with a need for a high Signal-to-Noise-Ratio. The product comes in an micro-ITLA formfactor and has an optimized firmware and electronics configuration to bring out superior performance.
The Pure Photonics tunable laser solution makes a field proven, high-volume telecommunications laser suitable for the high-demanding applications that are typically addressed by hand-crafted custom solutions. Not only does the technology provide optical performance at-par with the existing solutions, it does so in an extremely small form-factor and a tuning range as large as 60nm (default 38nm). Tunability allows our users to provide products that have an enhanced functionality and to significantly reduce leadtime and inventory cost.
Thanks to the ECL design, the intrinsic linewidth of the product is extremely narrow. No other volume manufactured tunable laser product can approach the 10kHz intrinsic linewidth that this product offers. In addition, thanks to a very stable design, without moving parts or current-injected tuning sections, the Gaussian noise at lower frequencies is also impressive.
With the low loss external cavity, the output power from the laser can be as high as 17dBm (default 13.5dBm). And the unique tuning control technology enables the laser to switch to any-frequency within its tuning range.
The optical cavity is formed by a gain chip and an external cavity with a high-reflection end-mirror. Within the cavity two Silicon etalon filters are positioned with a slightly different Free-Spectral-Range. The combined transmission curve, through the Vernier effect, selects the dominant laser peak. The frequency, in this way, can be independently tuned by changing the temperature of the filters, and the power can be independently tuned by changing the injection current in the gain chip.
The product is integrated with all electronics to control he product: the output power is controlled through an integrated photo-diode, the temperature of the filters is controlled through temperature sensors and the frequency lock is controlled through an imposed 888Hz dither signal. Thanks to the on-board micro-processor, the user only needs to provide digital commands (e.g. ‘set channel x’, ‘turn laser on’, etc) and does not need to control the underlying technology.
The described telecom-grade product has been deployed in high volume by Lumentum over the past 10 years and it has proven to be a very stable and high performance platform.
Pure Photonics is enhancing this product by providing significant reductions in laser FM and AM noise, as well as by enabling new operation modes, such as frequency sweeps and fast switching. This is done through optimization of control algorithms and improvement of electronics.
